Work-table for grinding-machines



E, B. GARDNER. WORK TABLE FOR GRINDING MACHINES.

APPLICATION FILED SEPT. 21, 1918.

Patented pr. 20, A19920o 3 SHEETS-SHEET I.

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E. B. GARDNER. WORK TABLE FOR GRINDING MACHINES. APPLICATION FILED sEPLzI, IsIa.

1,337,352. Patented Apr. 20, l1920.

E. Be GARDNER. WORI( TABLE FOR GRINDING MACHINES.

APPLICATION FILED SEPTLZI, |918. 1,337,352.

Patented Apr. 20, 1920.

3 SHEETS-SHEET 3.

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UNITED STATES PATNT FFUE.

EDWARD B. GARDNER, OF BELGIE, WISCONSIN, ASSGNOR TO BADGER TOOL COMPANY, 0F BELOIT, WISCONSIN, A CORPRATION OF WISCONSIN.

WORK-TABLE FOR GRINDING-MACHINES.

Application filed September 21, 1918.

To all whom t may concern:

Be it known that I, EDWARD B. GARDNER, a citizen of the United States, residing at Beloit, in the county of Rock and State ot fvlisconsin, have invented certain new and useful Improvements in Vork-Tables for Grrinding-h/lachines, of which the following is a specification.

This invention relates to the art of grind-- -mg machines and more particularly to a work-table for such machines comprising a support, a table top mounted thereon to slide toward and away from the grinding wheel, and means for moving said table top whereby the work clamped thereon may be pressed against the grinding wheel.

One of .the objects of the invention` is to provide improved means for moving the table top toward and away from the grinding wheel.

Another object is to provide adjustable means for limiting the travel of the table top in both directions.

In the accompanying drawings, Figure 1 is a side elevational view of so much of a grinding machine as is necessary to the understanding of my invention. Fig. 2 is a top plan view of the work-table detached. Fig. 3 is a longitudinal section through the work-table taken in the plane of line 3 3 of Fig. 2, and looking in the direction of the arrows. Fig. 4 is a sectional plan view in the plane of line l-l of Fig. 3. Fig. 5 is a rear end elevation of the work-table. Fig. 6 is a transverse sectional view in the plane of line 6-6 of Fig. 2. Fig. 7 is a transverse sectional view in the plane of line 7-7 of Fig. d. Figs. 8, 9 and 10 are detail views of the grinding wheel dresser, Fig. 8 being a plan view and Figs. 9 and 1() elevational views of opposite sides of the dresser. y y y For a general understanding of the relationship of the work-table in one form of grinding machine, reference may be had to Fig. l, which shows a disk grinder ot a well-known type equipped with a work-table embodying my invention. A fragment of: the body of the grinder is indicated at 11. 12 designates the grinding wheel, and 13 a bar which projects from the body of the grinder beneath the grinding wheel and constitutes the means on which the work support as a whole is mounted. A rocker box 14: is rotatably mounted on the bar 13 and has Specification of Letters Patent.

Patented Apr. 20, 1920.

Serial No. 255,022.

Ia slot or groove in which an upright bar 15 is slidably mounted, the bar being held in different positions by means or" set screws 16'to support the work-table at different elevations. A counterweight' 17 is iXed to the lower end of a rod 17 which is lixed to and depends from the sleeve portion of the rocker box 141. The counterweight thus serves to hold said bar 15 in upright position.

The work-table comprises a base or support 18 having a downwardly extending lug 19 overlapping a portion of the upper end of the bar 15, being pivoted at 20 thereto and having an arcuate slot 21 through which passes a screw or bolt 22 that is seated in the bar for rclamping the parts together in any desired position of angular adjustment. The parts so far described are of standard and well-known grinder construction, and i'form no part oi' the present invention.

The work-table further comprises a table top 23 slidably mounted on the support 18 to movel toward and away from the grinding wheel 12. rllhe particular shape or construction of the table top is not essential, but it preferably comprises depending flanges at opposite sides of the support 18, and two gibs 2d secured to said flanges and underlying the edges of the support. The upper face of the table is provided with undercut slots 25 through the medium of which the work may be bolted to the table top.l

The means for moving the table top bach and forward comprises two members 26 and 2T pivoted together at their adjacent ends, the remote ends ot said'members being pivotally attached respectively to the table top 23 and the support 18. In the present instance, the member 27 is fixed on the upper end of a shaft 28 which is rotatably mounted in a bearing of the support 18, the lower end of said shaft projecting through said support and having fixed thereon a horizontal hand lever 29 which projects laterally beyond one edge of the table to he grasped by the operator. The member 27 forms a crank on the upper end ofthe shaft 28 and the two members 26 and 2T together constitute a toggle connection between the table top and its support. The shaft 28 and the pivot 3() for the member 2G are located at or near the center oi' the table. By swinging the hand lever 29 toward the grinding wheel 12, the operator causes the members 26 and 27 to move toward a position in alinement with each other, thereby advancing the table top toward the grinding wheel.

lf a piece of work be fastened to the table top ready to be ground, it is desirable for the work to be pressed against the grinding wheel relatively lightly at first7 in order to smooth off any rough points or projections that might injure the grinding disk if the work were immediately forced against the disk under great pressure. s the grinding proceeds, the table top is advanced farther and farther under pressure of the lever and the pressure on the work is increased.

rlhe peculiar relationship of the parts of my operating means is such that it conforms to the most desirable mede of operation in grinding a piece of work. as above explained. When the crank member 27 is in its initial position with the table top retracted from the grinding wheel, said crank member' extends more or less laterally away from its shaft 2S with respect to the table, and therefore, a given movement of the hand lever 29 will advance the work-table a maximum distance. Continued movement of the hand lever carries ythe crank and link members of the toggle joint into a position more and more approaching alinement, during which movement the advance of the table top in a given arc of swinging of the hand lever becomes less7 but the power exerted on the table top with a given pressure on the hand lever is proportionately increased. Thus. as the grinding action of the wheel 'l2 on the work becomes slower, the rate of advance of the table top correspondingly slows up and the power exerted upon the table top iucreases so that the pressure of the opeiuater upon the hand lever 29 is utilized to its :naximum efliciency.

ln some of the work-tables heretofore known the operating means has exerted its power upon one corner of the slidable table top with the result that there was a tendency toward binding along the guides. T his binding tendency7 is entirely eliminated .in my table since the pressure upon the table top is exerted along the center line| of the table. My operating means is extremely powerful in action and at the same time the table top may be quickly advanced or withdrawn. These combined lattributes of great power and quick movement are very desirable in a work-table of this character.

The means for limiting the travel of the table top will now be described. A block 3l is fitted between the depending flanges and gibs 24- of the table top and lies alongside the rear end of the support 18, said block being suitably fixed to the table top as'by screws 32 (Fig. 7). A micrometer screw is threaded in this block and is arranged to abut against the end of the support 18 to limit inward travel of the table top. .l graduated head 341C on the screw cooperates with an indicator 35 projecting from the table top so that the variations in position of the stop screw may be observed. In the opposite end of the block 3l is a bearing, through which a rod 36 slidably passes one end of said rod being threaded or otherwise anchored in the support 18 and the free end of the rod having a head 37 or other stop adjustably fixed thereon and arranged to limit the travel of the table top in a rearward direction. The head 37 is slotted as seen in Fig. 5 and is arranged to be clamped 0n the rod 36 by suitable means such as a screw 3S.

In one edge of the table top is formed au undercut slot 39, in which is mount-cd a bracket 40 carrying a dresser-roller fi-l fia' dressing the face of `the grinding wheel. The bracket a() has a rib 42 8 and D) on one side entering the narrow 1)art of the slot 39, and a bolt a8 passing through a hole in the bracket has its head engaging in the wider part of the slot and has a nut on its outer end for clamping the bracket in any desired position on the table top.l rifhe forward end of the bracket is bifurcated to form two arms between which the dresserroller il is mounted on a pin or screw el. l/Vhen the grinding wheel is to be dressed. the bracket 40 is moved to the forward end of the work-table so that the dresser wheel il projects beyond such forward end. and the bracket is then clamped tightly in place. By means of the hand lever 29 the table top 23 may then be advanced to carry the dresser into contact with the grinding wheel and the work-table as a whole may be recited upon the bar 13 in the usual manner to cause the dresser to travel across the face of the grinding wheel.

The wheel dresser as a whole is located below the upper surface of the table top and is a small compact device so that it occupies little room and is never in the way. .lt may, therefore, be left attached to the wollt-table at all times.`

While l have described a preferred embodiment of my invention in considerable detail for Athe sake of clearness, l recognize the fact that various modifications may be made within the spirit and scope of thc invention, and I, therefore, aim to cover in the appended claims all equivalent and alternative constructions which fall within the scope of the invention. As an example of an alternative construction, it might be mentioned that while the member 2T of the toggle connection is, in the present instance, in the form of a crank attachment to the shaft -which carries the hand lever 29, it is not to the toggle members might be provided while still retaining the advantages of my invention.

The wheel dressing means forms the subject matter of my copending application Serial No. 278,277, filed February 20, 1919, which is a division of the present application.

I claim as my invention:

l. A work-table comprising a support, a table top slidably mounted thereon, a shaft journaled in said support, a hand lever iiXed on said shaft and adapted to be swung by the operator, and means disposed between said table top and said support and adapted to be actuated by said shaft for moving said table top with a gradually increasing force upon application of uniform force to said hand lever.

2. A work-table comprising a support, a table top slidable thereon, a hand lever mounted on said support, and means operable by said hand lever for moving said table top on said support with a gradually increasing force and correspondingly decreasing speed as said lever is swung on its pivot at a constant linear speed by a uniform force.

3. A work-table comprising, in combination, a support, a table top slidable thereon, a shaft journaled in said support, a handle iiXed on the lower end of said shaft, and means located in the space between said support and said table top and connecting the upper end of said shaft to said top for advancing said top when said hand lever is swung.

L A work-table comprising, in combination, a support, a table top slidable thereon, a pair of members pivoted together at their adjacent ends, the remote ends ot' said members being pivoted respectively to said support and said 'table-top, and means for swinging one of said members so as to cause said three pivot points to approach a common line to thereby move said table top with respect to said support with a gradually increasing force.

5. A worktable comprising a support, a table top slidably mounted thereon, a crank member pivoted on said support, a link pivoted at one end to said table top and at its other end to said crank, said crank and 'link being inclosed between said support and said top, and a hand lever connected to said crank whereby the crank may be actuated to move said top relatively to said support.

6. A work-table comprising a support, a table top slidably mounted thereon, a hand lever and mechanism operable by said hand lever for moving said top on said support with a gradually increasing force and decreasing speed, and said mechanism comprising relatively movable members arranged to exert va moving force upon said top along a substantially medial line.

7. A work-table comprising, in combination, a support, a table top slidable thereon, a stop screw carried by said table top and adapted to abut against a part of said support to limit the travel of the table top in one direction, a rod iXed at one end in the support, and a stop adjustably mounted on said rod arranged to form an abutment for a part on the table top to limit the travel of the table top in the opposite direction.

8. A work-table comprising, in combination, a support, a table top having sides and a rear end overhanging the sides and end of said support, a rod iXed at one end in said support and projecting slidably through an opening in the depending end of said table top, and a stop adjustably mounted on said rod and forming an abutment to be engaged by said end of the table top for limiting travelof the table top in one direction.

9. A work-table comprising, in combination, a support, a table top slidable thereon, means adjustably mounted on said top to abut against a part on said support :for limiting the travel of the top in one direction, and adjustable means carried by the support and arranged to be engaged by a part on the top for limiting the travel of said top in the opposite direction.

10. A work-table comprising a support, a table top slidably mounted thereon, a hand lever pivoted on said support, and means inclosed between said top and said support and operable by said lever to exert a moving force upon said top along a substantially medial line.

In testimony whereof, I have hereunto set my hand.

EDVARD B. GARDNER. 

